Catalytic combustion unit rco in coking plant

Catalytic combustion unit rco in coking plant

Catalytic combustion equipment parameters:

Pre purchase notice:

Our company integrates design, research and development, manufacturing, sales, construction, and after-sales service;

Engaged in the design, production, installation and commissioning of various industrial waste gas, dust, noise, desulfurization and dust removal, oil fume and smoke, ventilation and cooling projects;

Due to market price fluctuations, the prices and attributes of the above products are for reference only.

1、 Product Technical Principles

Designed based on the two basic principles of adsorption (high efficiency) and catalytic combustion (energy saving), it adopts dual gas path continuous operation, with one catalytic combustion chamber and two adsorption beds alternately used. Firstly, the organic waste gas is adsorbed onto activated carbon, and when it reaches saturation, the adsorption is stopped. Then, the organic matter is desorbed from the activated carbon using a hot gas flow to make the activated carbon; The detached organic matter has been concentrated (with a concentration several tens of times higher than before) and sent to the catalytic combustion chamber for catalytic combustion into carbon dioxide and water vapor, which are then discharged. When the concentration of organic waste gas exceeds 2000PPm, the organic waste gas can maintain spontaneous combustion in the catalytic bed without external heating. Part of the exhaust gas after combustion is discharged into the atmosphere, while the majority is sent to the adsorption bed for use as activated carbon. This can meet the heat energy requirements for combustion and adsorption, achieving the goal of energy conservation. Afterwards, it can enter the next adsorption; During desorption, purification can be carried out using another adsorption bed, which is suitable for both continuous and intermittent operations.

2、 Scope of application

The purification and elimination of harmful organic waste gases emitted or leaked from painting, printing, electromechanical, home appliances, shoe-making, plastic and various chemical workshops, as well as the elimination of odors, are suitable for organic waste gases with lower concentrations that are not suitable for direct combustion or catalytic combustion and adsorption recovery treatment, especially for high air volume treatment scenarios, and can achieve satisfactory economic and social benefits.

3、 Main features

The device is designed with advanced principles, materials, stable performance, simple structure, reliability, energy saving and labor-saving, and no secondary pollution. The equipment occupies a small area and is lightweight. The adsorption bed adopts a drawer type structure, which is easy to load and replace.

Low power consumption, the catalytic combustion chamber uses honeycomb ceramic shaped precious metal catalysts as carriers, with low resistance and high activity. When the concentration of organic waste gas exceeds 2000PPm, spontaneous combustion can be maintained.

Catalytic combustion unit rco in coking plant

Process Flow Diagram

Design: There are flame retardant and dust removal systems before and after the catalytic purification device, and a pressure relief system is installed at the top of the equipment.

Both inside and outside the equipment are equipped with anti-static devices, and high-altitude pipelines are equipped with lightning protection devices.

Multiple temperature control points are installed inside the device, along with an automatic alarm system and an over temperature automatic cooling system.

The equipment is equipped with fan overload protection, over temperature protection, and fire interlock protection. A fire valve is installed at the inlet of the equipment. When high temperature occurs, the fire valve closes and the direct discharge valve automatically opens.

When there is an error or malfunction in the control and monitoring system during desorption, the temperature controller will trigger an alarm to automatically stop heating, and the supplementary cooling system will automatically turn on. When a fault occurs suddenly during the operation of the desorption fan, the heating system and fan will interlock, and the heating will automatically stop, and the supplementary cooling system will automatically turn on and start the direct discharge system.

During the desorption process, 97% nitrogen gas is intermittently injected. After the desorption procedure is completed, 97% nitrogen gas is injected into the activated carbon adsorption bed to eliminate the hidden dangers caused by the self heating and self ignition of activated carbon.

Catalytic combustion bed

Catalytic combustion is a purification method that uses catalysts to oxidize and decompose combustible components in harmful gases at lower temperatures. For HC and organic solvents, steam oxidation and decomposition generate carbon dioxide and water, releasing heat.

Catalytic combustion requires mixing the harmful gases to be purified evenly and preheating them to the ignition temperature required by the catalyst, so that the combustible components in the harmful gases begin to oxidize and release heat.

The main functions of catalytic combustion bed are as follows:

1. After the internal heating element generates heat energy, hot air is blown into the activated carbon bed through a fan and connecting pipes to raise the temperature of the activated carbon bed;

2. After the adsorption process, the activated carbon vaporizes and decomposes organic matter from the activated carbon. Under the negative pressure guidance of the fan, the organic matter enters the catalytic combustion bed through the desorption pipeline and heats up again, and undergoes chemical reactions with the precious metal catalyst filled inside the catalytic combustion bed. The organic matter undergoes secondary decomposition and purification.

3. When the temperature of the catalytic bed reaches 250-300 ℃, the organic matter can begin to react, and the hot air generated by the combustion of exhaust gas is circulated for use. When the heat generated after the reaction reaches a certain value, the heating element can stop working (i.e. in a low-power operating state).

4. After the desorption of activated carbon, the low air volume and high concentration organic waste gas first enter the heat exchanger for heat exchange, achieving the recovery of waste heat. After the heat exchanger, the waste gas is further heated by a heater (using multiple sets of electric heating tubes for heating), and the heated organic waste gas reaches the ignition temperature of the waste gas under the action of the catalyst. The exhaust gas enters the catalytic combustion bed, and under the action of the catalyst, it is cracked into CO2 and H2O at high temperature, purifying the organic components. At the same time, the cracking of organic exhaust gas releases heat, further increasing the gas temperature. The purified exhaust gas is recovered and utilized through two-stage heat exchangers for waste heat recovery.

The preheating exhaust gas heating of catalytic combustion adopts a stable electric heating method. The electric heating tubes are divided into multiple groups and automatically controlled by the electric control box. PLC and system temperature interlock control are used. When the exhaust gas temperature is lower than the temperature (adjustable), the electric heating tubes will automatically turn on the power to heat the exhaust gas. When the exhaust gas temperature is higher than the temperature (adjustable), the electric heating tubes will automatically disconnect one, two, multiple or all power sources to save electricity and achieve operation. When the concentration of exhaust gas in the desorbed gas reaches around 4000mg/m3, it can basically achieve self balance of heat without the need to turn on electric heating, achieving the goal of energy conservation. Catalytic combustion reaction is a typical gas-solid phase catalytic reaction, which essentially involves the catalytic oxidation reaction between organic compounds (VOCs) adsorbed on the catalyst surface and oxygen from the air at temperature. The oxidation decomposes into harmless CO2 and H2O, and releases the heat of reaction. By using catalysts, the ignition temperature of organic matter can be significantly reduced for flameless combustion, reducing preheating energy consumption and NOx generation

5. Activated carbon desorption process: When the adsorption bed is saturated, the desorption fan can be started to desorb the adsorption bed. The desorbed gas first passes through the heat exchanger in the catalytic bed, and then enters the preheater in the catalytic bed. Under the action of the electric heater, the gas temperature is increased to about 280 ℃, and then through the catalyst, the organic matter is burned under the action of the catalyst, decomposed into CO2 and H2O, and releases a large amount of heat. The gas temperature is further increased, and the high-temperature gas passes through the heat exchanger again to exchange heat with the incoming cold air, recovering a part of the heat. The gas coming out of the heat exchanger is divided into two parts: one part is directly discharged; The other part enters the adsorption bed to desorb activated carbon. When the desorption temperature is too high, the supplementary cooling fan can be started for supplementary cooling to stabilize the desorption gas temperature within a suitable range. The temperature inside the activated carbon adsorption bed exceeds the alarm value.

Characteristics of this control system:

1. Adopting advanced PLC programmable controllers and touch screens with good human-machine interfaces, it is easy to adjust operating parameters and optimize operations;

2. Flexible switching between various operating modes such as test drive, automatic, standby, etc;

3. It can achieve automatic start stop operation.

4. The on-site electrical equipment, such as fan motors, temperature sensors, and pressure transmitters, are explosion-proof with an explosion-proof rating of ExDIIBT4.